.......all the possiblities! There are so many out there what do you prefer? I tie my own leaders most of the time, and keep them pretty simple. Depending on the situation I dictate the leader needed. Mainly it is all personal preference, but I want mine to turnover, especially when using indicator nymphing methods. Here are some of the formulas I have created that seem to work well....

I prefer longer leaders with spey fishing due to the fact that I usually fish them in bigger water. For smaller rivers, I usually adjust appropriatly. Place shot 6" above swivel, and one smaller one before dropper if needed.